Nuclear equation of state from observations of short gamma-ray burst remnants

Mar 26, 2014, 3:55 PM


Dr Paul Lasky (School of Physics, melbourne University)


The favoured progenitor model for short gamma-ray bursts (SGRBs) is the merger of two neutron stars that triggers an explosion with a burst of collimated gamma-rays. Following the initial prompt emission, some SGRBs exhibit a plateau phase in their X-ray light curves that indicates additional energy injection from a central engine, believed to be a rapidly rotating, highly magnetised neutron star. The collapse of this `protomagnetar' to a black hole is likely to be responsible for a steep decay in X-ray flux observed at the end of the plateau. I will show how these observations can be used to effectively constrain the equation of state of dense matter. In particular, I will show that the known distribution of masses in binary neutron star systems, together with fits to the X-ray light curves, provide constraints that exclude the softest and stiffest plausible equations of state. I further illustrate how a future gravitational wave observation with Advanced LIGO/Virgo can place tight constraints on the equation of state, by adding into the picture a measurement of the chirp mass of the SGRB progenitor.

Primary author

Dr Paul Lasky (School of Physics, melbourne University)

Presentation materials